Mixing apparatus



July 14, 1936. H. B. SIEMs MIXING APPARATUS Original Filed March 28, 1932 1K n n md .n H U 5 a e M M m A w M 2 Y .m .a :)HIL u i E m 1 Tu m x i W .w

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ATTORNEY )TNESJ maal/mr Patented July 14, 1936 UNITED -sTATEs PATENT OFFICE y 2.047.394 me mmrus Original application March 28. 1932, Serial No. 601,579. Divided and this application January 10, 1934, Serial No. 706.089

4 Claims.

This invention relates to an apparatus for preparing fertilizer and is a division of my application entitled Acid treatment of solids, Serial No. 601,579, filed March 28, 1932, in response to which Patent No. 1,989,175 was granted January 29, 1935.

One of the objects of the invention is to provide an apparatus for use in connection with certain types of mixing operations wherein the Ysalt produced by the interaction of an alkali and an acid is formed in a mixing chamber containing solids composed of granular particles of relatively large diameter and smaller particles of graduated size down to the size of fine powders. Such mixing is frequently employed in the production of fertilizers wherein in accordance with this invention, an alkaline reacting liquid or gas, or both, may be injected simultaneously with the injection-of a suitable acid, into the mixing chamber containing the other ingredients of the fertilizer in such manner as to provide a spray of the 1re-agents. The salt resulting from the interaction of the acid and alkali spray is thus formed and directly mixed with the other constituents.

It will be seen that the apparatus herein described and claimed may be used advantageously for the production oi fertilizer in the manner described and claimed in my copending application entitled Fertilizer preparation, Serial No. 706,088, led January l0, 1934, which application is also a division of my application entitled Acid treatment of solids, Serial No. 601,579, in which case the fertilizer mixture may comprise such mixtures as super-phosphate, sulphate ci ammonia, nitrate of soda, tarikage, potashsalts, treble super-phosphate, etc.

The salt produced by the acid and alkali spray is that resulting from the inter-action of acids such as sulphuric or phosphoric with anhydrous ammonia, aqueous ammonia, or any other reagents productive oi the particular salts desired.

` Accordingly, it is an object of this inventionto provide a new and improved apparatus by which a salt is produced as the result of the lnter-action oi' acid and alkaline re-,agents which are brought together in a manner to form a spray whereby the re-agents commingle and react to produce the desired salt.

It is a further object of this invention to provide an apparatus for accomplishing this object which involves the use of anhydrous ammonia and a partial neutralizing action between the acid and ammonia and subsequent commingling oi.' the re-agents in the form of a spray, together with the utilization of the heat of neutralize-t,

tion for raising the temperature of the spray to thereby avoid all danger of the liberated ammonia freezingthe acid. f

A further object of this invention is to provide an apparatus for accomplishing these objects which utilizes the heat of the initial and partial neutralizing reaction for heating the re-agents for'the final neutralizing reaction produced by the commingling of the sprayed re-agents.

'It will be seen that this apparatus may be advantageously applied to mixing operations and particularly to the type involved in the production of fertilizers such as that of producing a salt in the mixing chamber by commingling the sprayed re-agents whereby as a result, the finer or powdered particles of the solid materials are caused to adhere to or coat the larger particles, or many small particles are caused to be cemented together, thereby -resulting in a final mixture in which all of the particles are more nearly of the same size and physical appearance.

Other objects will be apparent from the description and claims which follow.

The single lgure of the accompanying drap/- ing isa somewhat diagrammatic elevational view of an apparatus constructed in accordance with this invention and designed particularly for the yproduction of fertilizer. It is believed that the legends on the mwmg bring out clearly the purposes oi the several parts.

By referring to the drawing lt will he noted that the disclosure includes a mixing drum it, Winch may he ci any suitable size and construction ier use in inlring solid materials such as those conunonly employed in fertilmer mixtures. .as here illustrated, the drum is oi the rotary type mounted on suitable roller bearings l2, carried by the support i3, andthe drum may be driven from any suitable source oi power (not shown) hy means of a pinion in mesh 'mth a ring gear it, attached to the drum.

'The drum is preferably provided with a number of blades il on the interior thereof tu assist in the mixing operation. The solid material may be fed to the drum through a pipe I 8 from Pipe I8 is connected to the non-rotatable part l5, so that the material may be ted to the drum while the drum is rotating. `lipes or conduits 43 and 45 may be extended into the central part of the drum substantially as shown in the drawing. Opposite the stationary part I5, and centrally of the drum, a discharge device 50 may be provided having an inclined upper surface. 'I'his apparatus is likewise stationarlly mounted and while the drum is rotating, is maintained in the full line position shown in the drawing but is adapted to be moved inwardly to the dotted line position for eifecting a discharge of the mixture.

The material pipe I8 is preferably provided with a valve I8 to prevent the escape of gases before the neutralizing action has been completed. It is obvious that the neutralizing apparatus here referred to may be used in connection with any suitable operation and that the particular construction of the drum here shown is merely for the purpose of illustrating the inventionA as applied in the manufacture of the fertilizer.

The apparatus for providing the salt above referred to will now be described. The pipe 20 having a valve 2| is connected to a source of mineral acid such as sulphuric or phosphoric acids and also by means of pipe 22 to the bottom of the measuring tank 23. The measuring tank is provided with a graduated sight gauge 24, so that by operation of the valve 2I, any measured quantity of acid may be. introduced into the tank. In feeding the acid to the tank, and during the discharge thereof, the tank is vented to the atmosphere by means of a petcock 25. After securing the desired amount of acid, valve 2| is closed and the acid may thereafter be discharged through pipe or conduit 26, having a valve 21 therein which may be open so that the acid will be fed directly into the reacting vessel 28. In the drawing, the vessel is shown in cross section whereby to disclose the interior construction thereof.

In addition, a pipe 3U is provided having a shutoff valve 3i which pipe connects at one end to a suitable source of alkaline reacting substance such as anhydrous ammonia, aqueous ammonia, or any other desired alkali, and at its other end, through pipe 32, to a measuring tank 33, of substantially the construction of the tank 23. This tank also has a sight gauge 34, and an air vent petcock 35. Leading from the pipe 32, is the pipe 35 having a shutoff valve 31. This pipe branches to form pipes 38 and 39.

Pipe or conduit 3B passes downwardly into the mixing vessel 28 and thence upwardly and terminates as at 39 whereby to serve as a discharge for the alkaline substance in the reacting vessel. Pipe 38 is provided with a control Valve 4I] and a pipe 39 with a control valve 4I, so that the exact amount of alkali passing through each pipe may be readily adjusted. It will be further noted that pipe 39 likewise passes into the reacting vessel but instead of opening to the interior thereof, passes therethrough in the form of a coil 42 and thence outwardly and downwardly by means of pipe 43. The bottom of the mixing vessel has inclined walls as at 44 which terminate in a downwardly extending discharge pipe 45. Discharge pipe 45 passes through the casing I5 of the mixing drum substantially as shown in the drawing and terminates in a discharge nozzle 46. ThisV nozzle is shown as discharging downwardly. Likewise the pipe 43 passes through the walls of the casing I5 and terminates in a discharge nozzle 41 which is arranged in close proximity to the nozzle 46 but preferably at right angles thereto.

In operation, the desired reaction between the acid and the ammonia or other alkali is brought about in the following manner. After the desired measured quantity of acid and alkali have been collected in tanks 23 and 33 respectively, valves 4I) and 4I are adjusted to control the quantity of alkali fed through the two branch pipes 38 and 39. Thereafter valves 21 and 31 are opened whereby the acid is permitted to pass into the reacting vessel 28 and the alkali is permitted to pass into the branch pipes 38 and 39.

'I'he portion of the alkali which by way of illustration may be anhydrous ammonia, passing into pipe 38, discharges into the reaction vessel to cause a neutralizing reaction with the acid.

The reacting vessel is preferably charged with a suitable filling material such as coke or other similar material which will not be attacked by the acid but will cause the acid to expose considerable surface as it trickles over the particles thereof.

Thus in the reacting vessel, the acid enters and is distributed with a large surface exposure throughout the coke mass in the vessel whereby it is brought in reacting contact with the ammonia or other alkali discharging from the outlet 39' of the pipe. This neutralizing reaction is exothermic and accordingly, a considerable amount of heat is liberated in the reacting vessel. The amount of ammonia introduced through valve 40 is regulated in such manner that the ammonia does not completely neutralize the mineral acid whereby no solid phase separates out at the temperature attained in the reaction vessel. Thereafter, the acid in the reacting vessel which has been partially neutralized and the temperature of which has been elevated considerably, is then discharged downwardly through pipe 45 and out through the nozzle 46.

The ammonia fed through pipe 39 passes through the coil 42 in the reacting vessel and thence through pipe 43 to the discharge nozzle 41. By passing the ammonia through the coil 42, heat of neutralization is imparted to the ammonia which not only raises its temperature but causes a larger volume thereof to exist in the gaseous phase. The heat likewise raises the temperature of the partially neutralized acid whereby freezing of the acid during the atomizing action is avoided.

The mixture of acid and dissolved salt which is delivered at 46 is met by a mixture of gaseous and/or liquid ammonia issuing from the nozzle 41. By virtue of the fact that the nozzles are arranged to discharge in different directions and the ammonia gas and/or liquid held under pressure is caused to discharge from the nozzle 41 with considerable velocity, the gaseous and liquid ammonia mixes with the hot acid and dissolved salt issued from the nozzle 46 in such a manner as to produce a iine spray. This spray establishes a commingling of the re-agents within the region of the mixing chamber whereby the desired salt is produced in the manner above described. In addition, the powdered particles of solid material are caused to be cemented together to form larger particles so that a fertilizer mixture of particles of substantially uniform size and physical condition results.

In the above illustration which relates to the production of fertilizer, the alkali employed is anhydrous ammonia. As it is usual for anhydrous ammonia to be supplied from a container under pressure so that it will normally exist in liquid form, the ammonia injected from nozzle 41 will have considerable velocity and therefore an atomizing effect upon the acid discharged from 'nozzle 41. It is the discharge of the ammonia in either gaseous or liquid form or a mixture of both, that is productive of the spray of the re-agents producing the salt.

In the event the process is used with other alkaline re-agents, it is of course understood that the alkali can be discharged under pressure by any suitable means such as supplied by a pump or a gaseous pressure on 4the liquid. In such case,

animos the alkali will be caused to discharge with considerable force, and thereby produce the desired atomizing eect with the acid.

With anhydrous ammonia, the heat of neutralization developed inthe reacting vessel serves to pre-heat both the acid and the ammonia whereby to avoid the danger of the ammonia freezing the acid and clogging the nozzle 46 and otherwise interfering with the process.

This precaution is exercised because the r'efrigerating effect of the discharge ammonia may, in some instances, prevent the successful neutralizing action by freezing the sub-divided particles of acid and thereby clogging the nozzle and preventing neutralization. Anhydrous ammoniawhich is kept in tanks, exists to a large vextent in liquid form and the pre-heating in the coil 42 also serves to assure the existence of a substantial amount of the ammonia in the gaseous phase after passing valve l I so as to produce the maximum atomizing effect. With ammonia and acid such as sulphuric or phosphoric acids above referred to, in addition to the mechanical atomizing eifect of the discharging gas, the action is enhanced by what may be considered the explosive effect of the rapid formation of steam resulting from the neutralizing reaction as expanded by the heat of neutralization. This causes drops of acid to explode and to become atomized and therefore more uniformly distributed.

It is to be understood that the invention is not to be limited by the disclosure herein given which is merely by way of illustration as the scope of the invention may be determined from the appended claims.

I claim:

1. In a fertilizer mixing apparatus comprising an acid supply tank, an alkali supply tank, a reaction vessel and a reaction chamber, a main alkali supply conduit extending from said alkali supply tank to said reaction chamber, an ancillary alkali supply conduit communicating with said alkaliv supply tank and terminating within said reaction vessel, an acid supplyl conduit extending from said acid supply tank and terminating within said reaction vessel, a reaction vessel conduit extending from said reaction vessel and terminating within said reaction chamber, said main alkali supply conduit passing through said reaction vessel in heat exchange relationship therewith, vthe terminals of said main' alkali supply conduit and said reaction vessel conduit positioned within said reaction chamber in close proximity to each other and so positioned that streams of iluids emitted from the terminals of f said two conduits forcibly meet and are thereby atomized.

2. In a fertilizer mixing apparatus comprising an acid supply tank, an alkali supply tank, a reaction vessel and a reaction chamber, a main alkali supply conduit extending from said alkali supply tank to said reaction chamber, an ancillary alkali supply conduit communicatingwith 'said alkali supply tank and terminating within said reaction vessel, an acid supply conduit extending from said acid supply tank and terminating within said reaction vessel, a reaction vessel conduit extending from said reaction vessel and terminating within said reaction chamber, i

said main alkali supply conduit passing through said reaction vessel in heat exchange relationship therewith, the terminals of said main alkali supply conduit and said reaction vessel conduit positioned within said reaction chamber in close proximity to each other and so positioned that streams of fluids emitted from the terminals of said two conduits forcibly meet and are thereby atomized, and means to regulate the proportion of iiow from said alkali supply tank through said main 15 alkali supply conduit and said ancillary alkali supply conduit.

3. In a fertilizer mixing apparatus comprising an acid supply tank, an alkali supply tank, a reaction vessel and a reaction chamber, a main alkali 20 supply conduit extending from said alkali supply tank to said reaction chamber, an ancillary K alkali supply 'conduit communicating with said alkali supply tank and terminating within said reaction vessel, an acid supply conduit extending 25 from said acid supply tank and terminating within said reaction vessel, a reaction vessel conduit'V extending from said reaction vessel and terminating within said reaction chamber, said main alkali supply conduit passing through sala reac- 3 tion vessel in heat exchange relationship therewith, the terminals of said main alkali supply conduit and said reaction vessel conduit positioned within said reaction chamber in close proximity to each other and so positioned that streams of fluids emitted from the terminals of said two conduits forcibly meet and are thereby atomized, said reaction vessel iilled with granular material.

4. In a fertilizer mixing apparatus comprising 0 an acid supply tank, an alkali supply tank, a reaction vessel and a reaction chamber, a main alkali supply conduit extending from said alkali supply tank to said reaction chamber, an ancillary alkali supply conduit communicating with said alkali supply 'tank and terminating within said reaction vessel, .an acid supply conduit extending from said acid supply tank and terminating within said reaction vessel, a reaction vessel conduit extending 'from said reaction vessel and terminating within said reaction chamber. said main alkali supply conduit passing through said reaction vessel in heat exchange relationship therewith, the terminals of said main alkali supply conduit and said reaction vessel conduit positioned within said reaction chamber in close proximity to each other and so positioned that streams of uids emitted from the terminals of said two conduits forcibly meet and are thereby 00 atomized, said reaction chamber provided with an inlet for solid fertilizer material adjacent the terminals of said supply conduits and a mixer positioned below said inlet and said terminals.

HERMAN B. SIEMB. 

